Field of the Invention
The present invention relates to a process cartridge and an electrophotographic image forming apparatus.
Description of the Related Art
In an electrophotographic image forming apparatus and a process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, a cleaning member is provided in order to remove a discharge product adhering to and a toner remaining on an electrophotographic photosensitive member (hereinafter, photosensitive member), after a toner image has been transferred onto an object to be transferred such as paper or an intermediate transfer member, from the photosensitive member. Among these cleaning members, a cleaning blade using a reed-shaped elastic member such as polyurethane rubber is known.
It is known that this cleaning blade system is apt to cause a lowering of scrapability due to wear and chipping of an edge at a tip end portion, and when the scrapability has been lowered, an object to be removed remains on the photosensitive member and causes a streaky image failure.
In Japanese Patent Application Laid-Open No. 2001-75451, a cleaning blade is disclosed, the tip end portion of which is highly hardened by increasing a concentration of an isocyanurate group at the tip end portion of the cleaning blade formed of a polyurethane elastomer. It is attempted to thereby lower the friction between the photosensitive member and the cleaning blade, and to improve a cleaning failure due to wear of an edge.
In addition, in Japanese Patent Application Laid-Open No. 2012-53311, an attempt is made to suppress wear and chipping of an edge by optimizing the hardness of a tip end portion of a cleaning blade.